A synthetic pathway has been constructed for the production of glucuronic and glucaric acids from glucose in Escherichia coli. Coexpression of the genes encoding myo-inositol-1-phosphate synthase (Ino1) from Saccharomyces cerevisiae and myo-inositol oxygenase (MIOX) from mice led to production of glucuronic acid through the intermediate myo-inositol. Glucuronic acid concentrations up to 0.3 g/liter were measured in the culture broth. The activity of MIOX was rate limiting, resulting in the accumulation of both myo-inositol and glucuronic acid as final products, in approximately equal concentrations. Inclusion of a third enzyme, uronate dehydrogenase (Udh) from Pseudomonas syringae, facilitated the conversion of glucuronic acid to glucaric acid. The activity of this recombinant enzyme was more than 2 orders of magnitude higher than that of Ino1 and MIOX and increased overall flux through the pathway such that glucaric acid concentrations in excess of 1 g/liter were observed. This represents a novel microbial system for the biological production of glucaric acid, a “top value-added chemical” from biomass.
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机译：已经构建了用于从大肠杆菌中的葡萄糖生产葡糖醛酸和葡糖二酸的合成途径。来自酿酒酵母的编码肌醇-1-磷酸合酶（Ino1）的基因和来自小鼠的肌醇加氧酶（MIOX）的共表达导致通过中间体肌醇产生葡萄糖醛酸。在培养液中测得的葡萄糖醛酸浓度最高为0.3 g /升。 MIOX的活性受到速率的限制，导致肌醇和葡萄糖醛酸作为终产物以大约相等的浓度积累。包含第三种酶，丁香假单胞菌的尿酸盐脱氢酶（Udh），有助于葡萄糖醛酸转化为葡糖二酸。该重组酶的活性比Ino1和MIOX的活性高2个数量级以上，并且通过该途径的总通量增加，因此观察到的葡糖二酸浓度超过1 g /升。这代表了一种新的微生物系统，可用于生物合成葡糖二酸，葡糖二酸是生物质的“高附加值化学品”。
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